I have a 99 RX 300 with 145k miles. Last year I had the transmission rebuilt and it has been giving me issues since. One hour after we picked the car up from the shop, it threw a P1153 code. I didn't think much of it, I'm pretty mechanically inclined, so I would check the MAF and/or replace the 02 sensor. Before I had a chance to do this, as my wife was driving to the store, it locked itself out of overdrive and started running rough and threw these codes: P0300 Random Cyl Misfire, P0302 Cyl 2 Misfire, P0304 Cyl 4 Misfire, P0306 Cyl 6 Misfire, P0171 Fuel System Too Lean Bank 1, P1153 A/F Sensor Response Bank 2 Sensor 1, B2798 Communication Fault #2 (Keyfob). I took it back to the shop that worked on the transmission and they told me it looked like the ECM was faulty, I called the Lexus dealership in Fort Wayne, In and they are saying that it's rare to find an ECM faulty. Also, the keyfob has always given me issues, sometimes working and sometimes not, only unlocking the drivers door. It's looking like it will cost me an arm and a leg to take it to the shop, so I need some help! If i reset the ECM it will drive fine for a few hundred miles, first the P1153 codes comes on and then shortly after that the other ones follow and lock me out of overdrive.